e-Beam Lithography_精品.ppt

e-Beam Lithography Antony D. Han Chem 750 U of Waterloo 06-02-07 * What is lithography? Original meaning: a process of printing using a non-polar ink applied to a hydrophilic master plate patterned with a hydrophobic image. Modern usage The term is more generally applied to a number of methods for replicating a predetermined master pattern on a substrate. Replication is effected by first coating the substrate with a radiation-sensitive polymer film (a resist) and then exposing the film to actinic radiation in a pattern-wise manner. The radiation chemistry that results alters the physical or chemical properties of the exposed areas of the film such that they can be differentiated in a subsequent image development step. Most commonly, the solubility of the film is modified with the radiation chemistry either increasing the solubility of exposed areas (yielding a positive image of the mask after develop) or decreasing the solubility to yield a negative-tone image of the mask. Widely used in semiconductor industry and IT industry. Focused eBL: ~sub 50 nm resolution * Steps involved in the EBL process. With a beam current of 600 pA and an accelerating voltage of 100 kV, the beam diameter was approximately 3 nm. J. Phys. Chem. B 2002, 106, 11463-11468 * e-Beam Lithography Electron source: SEM Equipment: SEM equipped with a pattern generator and alignment system e-beam control: accelerating voltage (kV) operation current (pA) exposure dose (μC/cm2) exposure dwell period (μs) * eBL followed by SA Langmuir, Vol. 20, No. 9, 2004, 3495 * eBL changes the properties of coating layers Langmuir, Vol. 20, No. 9, 2004 3767 * Applications of eBL (a) Backscattered electron (BSE) image of ZnO patterns on SiOx substrates annealed in air at 700 °C for 20 min (b) secondary electron (SE) image before annealing (c) SE image after annealing at 700 °C for 20 min in air (d) SE image of annealed patterns over a large area. Nano Lett., Vol. 5, No. 9, 2005 * Applications of eBL Proceedin